Rapid Identification of Chemical Compounds in Danzhi Jiangtang Capsule Using Ultra‐Performance Liquid Chromatography Quadrupole Time‐of‐Flight Mass Spectrometry Combined With Multiple Data Processing Techniques

Danzhi Jiangtang capsule (DJC) is a traditional Chinese medicine prescription that has been clinically used to treat Type 2 diabetes mellitus and its complications. However, research on the chemical compounds present in DJC remains limited. In this study, an analytical strategy based on ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) was developed for the rapid and systematic characterization of chemical compounds in DJC. Firstly, a DJC self-built database was established, and UPLC-Q-TOF/MS was applied for comprehensive profiling of DJC's chemical compounds. Then, R language combined with MZmine was used for data preprocessing to construct the ion information list and extract effective data. Finally, the compounds were identified by multiple data processing techniques (multiple-point screening mass defect filtering [MDF], extracted ion chromatogram [EIC], neutral loss filter [NLF], diagnostic fragment ion filtering [DFIF], and direct identification method [including retention time, fragment behavior and reference substances]). Eventually, 137 compounds were characterized from DJC, including 19 monoterpenoids, 26 triterpenoids, 8 flavonoids, 12 iridoids, 7 phenylethanoid glycosides, 8 acetophenones, 23 organic acids, 2 violet ketones, 13 cyclic peptides, 8 alkaloids, 2 fatty acids, and 9 other compounds. Among these, 16 compounds were verified using reference substances. The study indicated that the analytical strategy established in this study effectively supports the in-depth study of DJC's chemical constituents and provides essential data for subsequent in vivo studies.